High pressure gas compressor



E. PRE-:STAGE 1,805,741 HIGH PRESSURE GAS COMPRESSOR I.

May 19, 1931.

Filed sept. 25, 195o fand l in some chines.

Patented May 19, 1931 UNITED STATES EDWIN IPRESTAGE'OF LONDON, ENGLANDASSGNOR 0F ONE-HALF TO-IBROM & WADE I LIMITED, 0EY HIGH wYcoMBE, GREAT BRITAIN HIGH PRESSURE GAs icoivrrEEsso'R f Application med september 25, 19,30,V serial 110.1184377, and in Great, Britain'xuly 21, 1930.k

Thevpresentinvention relates to improvements in those high ypressure gas compressors described in UnitedStatespatent application Ser.y No. 435,246, in which a sleeve valveis arranged .between the piston and the cylinderfand reciprocated in a partly contraryy direction to the piston. ,f In thecompressors described in these patent.` specifications the dischargeports .for the kgas are Aformed inthe sleeve valve above the suction ports and these -fportsco-actwithla valve or a lseries Vof valves set behind 'o r, above these ports but actually on the sleeve.- The above valvearrangements have been found [very vsatisfactory in thosehigh pressure gasv compressors inwhich watergjacketsare not used. In certain; cases 1t 1s necessary to lprovide water vcooling. means, particularlyin those compressors designed forV compressing air v classes .of refrigerating yma- The highA speed valve compressor forming the present invention allowsiof the point of discharge through the automatic'valve or valves taking place much later in the stroke than hereto possible, so that the velocity of discharging gas is lower than in any otherV typeof compressor running at the same piston speed. Further, the present` machine isdesignedto present a large cooling lsuryfaceto the gas or Aair passing through-the Aeis machine during the compression stroke.

Briefly stated the present invention ,y comprises a sleeve valve compressor V1n which the-compressed air ory gas passesfrom the cylinder into a channel-or annulus atthe end of the compression stroke and is trapped. in said annulus andthen' expelled therefromv by the upward movementnof the sleeve.

'Myinventionis illustrated by Way; Of example inthe Yaccompanying` drawing which shows` a sectional elevation ofthe compres- Vsor cylindery with a portion-of` thejunk ring ande linder head ini-ull; v.

Y Re erring now to the drawing, la sleeve 1 .with inlet ports2 is reciprocated vwithin the cylinder' 3 in a partly contrary ldirection to `the piston 4. During the down stroke of iston 4 `the sleeve l moves upwards bringing Y.the ports y2' in `line with slot 5A which G is lPMENT OFFICE! EUGKINGHAMSHIRE, ENGLAND, A 'COMPANY v0E j machined through cylinder wall into suction annulus 6 which is connected in turn with the atmosphere or gas inlet pipe through opening 7 .G rWhen the piston 4 reaches the bottom oitv its stroke the sleeve l cuts off ports 2 from communicating with the cylinder andfcompression of the .contained alr-or gas proceedsias the piston 4 moves upward. At'about; half stroke thejtop .of sleevel comes below the cut 0E edge of piston or junk ring 8 thereby allowinglthe air .or gas undergoing compressionto flow into theannulus-9 formed bythe cylinder 3 and cylin- .n

f airor gas is trapped. y. As the piston 4 moves downwardV on its `next suctionl stroke, lthe ytop of ,the sleeve l'moves upward'sinto; the vannulus 9'pushing the air or gas in `this space upthrough the valve or f valves 11"v the gas is admitted to the cylinder through the lower portsQin the sleeve as the piston descends-,which ports are shutowingto'the downward travel ofthe sleeve when the piston reaches the bottom of its stroke .`Dur

piston .the Ytop of the sleeve movesdownbelow the recessed piston ring V8 onzthe cylinder head. The top of the sleeve comes below the cut off edge voi? the piston ring 8 at yabout half stroke, and byexposingtothe Cx l `which are resting on the seat 12. As stated 1'" .ing thev upward or compression stroke ofthe Y cylinder the annulus9 in whichfit `reciproy' I n this )manner a-relatively longnarrow' waterKA cooled Vchannel is Vprovided for, the l pression, whichresults inthe compression cates, 'allows the vair or in processof compression to expand into this space.`

vair or gas Vjustat the ycritical momentlwhen l the greatest heat isbeingrgeneratedlby com- Y `being much nearer` isothermallthan would otherwise beV the case. Just asrthepiston reaches the top of its stroke the top of vthe sleeve, which is now moving' upwardcuts v foil" on thededge of said .piston or junk ring der head and the inner wall of said cylinder in a partly contrary ydirection to said piston and adapted to first trap the air'or gas compressed into said annulus on the upward stroke of the piston and then to expel said air or gas therefrom through the outlet valve on its continued upward movement through said annulus and a recessed junk ring surrounding the projecting end of said cylinder headadapted to co-act with said sleeve valve to trap the ycompressed air or gas in said annulus before it is' expelled therefrom by said v valve.

p In testimony whereof I have signed 'my name, to this specification.

EDWIN PRESTAGE. 

